Art of and apparatus for casting fluid metal.



H. H. DOEHLER.

ART OI AND APPARATUS FOR CASTING FLUID METAL.

' APPLICATION I'IIIED JAN. 12, 190B. 7 973,4 3,. I I Patented 001;.25,1910.

' B'SHEE'IS-BHEET 1.

i Atty.

. n m n e V m M 0 H m 1 i I n 0U f l'n h- I HHJIJUI L v. .m uw m A a Ln- WA E h M he I 9 H y 1 a b on ll] Ml- IIIIIIIW II lllllllllllml H. H.DOEHLER.

I ART OF AND APPARATUS FOR CASTING FLUID METAL.

Paitented Oct. 25, 1910.

APPLICATION FILED JAN. 12, 1909.

2 SHEETS-SHEET 2.

. the borough of Brooklyn, city of New HERMAN H. DOEHLER; OF NEW YORK,N. Y;

ART or AND APPARATUS ron GASTING FLUID METAL.

Specification of Letters Patent.

Patented Oct. 25, 1910;

Application filed January 12, 1909. Serial No.'47 1,886

To all whom itma'y concern:

Be it known that I, HERMAN H. DOEHLER, a citizen of the United States,residin or county of Kings, and State of New York, have invented certainnew and useful Improvements in the Art of and Apparatus f0 Casting FluidMetal, of which'the following is a specification, reference being hadtherein to the accompanying drawings, which form a part thereof.

My invention relates to the art of and apparatus for casting fluid metaland more particularly for casting such metal under elastic fluid,pressure, or compactin and compressing-the cast fluid in the mold.

There have, heretofore, been devised various methods and apparatus forcasting.

' fluid metal in molds and compressing or 'acter of the metal cast, orthe character ofcompacting the same therein,'but the nature thereof hasbeen such as to restrict the charthe mold used, thus placing limitationsupon the art and the apparatus which would make them impracticable forhigh class work or for commercial use. In most cases, excepting inprocesses and apparatus in use in making dental plates, or similararticles, wherein but one article is made from a mold, the metal beingcast is drawn directly from a melting pot filled with metal kept in afluid state by a furnace surrounding said pot, a pumping or forcingmember bein" submerged in this metal with the twofol object of aconvenient withdrawal of a portion of the metal for use in casting, andthe maintenance of high temperatures in the pumping or forcing member toprevent the chilling of the metal and that obstruction of the memberresulting therefrom. This type 'ofapparatus is capable of high,eflicienc with metal having a low fusing point, suci as zinc, and tinmixtures, although even with such, in most alloys the metal deterioratesrapidly, becomes rapidly oxidized, and loses its strength and utilityfor making castings, by reason of the continued heatmg thereof, thepresence of dross and OKlClS, and that affinity of the alloy for themetal entering into the apparatus. These objections apply to practicallyall of the white metal alloys having a low fusing point, and in additionto these objections, it is imposslble t'ouse an alloy having ahighfusing point in this type; of apparatus because of the intense heatrequired to flux same and the increased tendency of the alloy to consumethe apparatus when-the metal is fluid or t, braze the various movingarts thereof tggether when the metal chil s. Ithas be 11 suggested thatthe substitution of an elastic fluid such as compressed air forforcing-the metal and compressing it in. the mold, would o'bviate theseobjections, but I have found that to withstand the high temperatures.within a melting pot, it would be necessary to use materials in makingthe melting pot, and the pressure pot, which would withstand the hightemperatures, such as lava,or graphite, and that the strength of thesematerials is not such as to withstand the heavy pressure necessary toeffect that high degree of compression of the metal in the mold,necessary to secure perfect castings with good sharp outlines. It hasalso been suggested in connection with the manufacture of car wheels,pig iron or other similar articles that "the fluid metal be first pouredinto the mold and thereafter subjected to pressure from a mov; ing partof the mold or compressed air, to compact same. This proposed process isimpracticable as failing to secure that re- 1 cision in the castingrequired in high 0 ass work and furthermore as being inoperative withalumlnum or brass alloys or even white metal alloys, which when cast setin the mold and chill almost instantaneously.-

The main object of my invention is to provide a method of casting fluidmetals having a high fusing point, such as brass or aluminum, capable ofbeing conducted under such conditions .as will permit the production ofcommercial castings in large quantities from 'one'and the same mold.

A further object is to provide a method of this character whereina'substantially,

exact quantity of fluid metal will be rapidly conveyed to the mold andbe practically simultaneously subjected to high pressure,

so that the pouring and compressing will be:

substantially simultaneous and thus avoid those imperfections in thecastings which Wouldresult were the metal permitted to set, even throughthe chilling of the portion thereof contacting with the mold beforesubjected to pressure.

A still further object is to provide a method or art of-the characterdescribed, wherein the elastic fluid pressure relied upon to compress orcompact the metal. in the mold, will also serve to increase therapidityof the charging of tl1e,mold; and wherein metal being-cast will bedestroyedewith the heavier pressure outside the mold to avoid theimprisonmentof air in the metal being cast, either by the splashing ofthe metal prior to its entering the mold, or a rotary movement orswirling of themetal after it enters the mold, or the compression of airbetween the incoming metal and the walls, abutments or angles of or -inthe mold.

A still further object is to provide a method or art by which the moltenmetal will be first poured, and after pouring be followed up by fluidpressure while it is concentrated in and flowin slowly through aconstricted channel passing to the mold, whereby the metal will enterthe mold and be compacted therein under high pressure with a resultantperfect casting with sharp outlines.

A still further object is to provide an apparatus for carrying out theaforesaid process, art or method which may be used without subjectingsame to those high temperatures necessary to reduce the metal to a fluidstate and which will withstand the high pressure used in carrying outsaid process, art or method.

A still further object is to rovide an apparatus of this characterutilizing compressed air for charging and compressing;

the fluid metal, which embodies therein a pressure chamber through whichthe molten metal is introduced to the apparatus, said pressure chamberbeing so constructed that the flow of the metal will be so directed andcontrolled as to avoid a jet of air being directed upon the surface ofthe molten metal, with a resultant splashing of the metal, reduction inthe quantity of same passing to the mold, the imprisonment therein ofair from. said jet, or its entrance to the mold ahead of the fluidmetal.

A still further object is to provide in an apparatus of this character aremovable ladle which will have the twofold features of non-conductivityto prevent the chilling of the metal prior to its introduction to theapparatus or the mold, and suflicient strengths to resist the highpressures prevailing in the pressure chamber during the process ofcasting.

A still further object is to provide in an apparatus of this character aladle which may be inverted for the purpose of pouring the metal intothe mold and when so inverted will act to receive the air currentthereon, deflect it from a straight course and protect the fluid metaltherefrom until it has left-the pressure chamber and is flowing towardthe mold.

A still further object is to provide in an apparatus a removable ladleadapted to be mounted in a closed pressure chamber, the bearing of whichwill be so constructed as to cause the pressure within the pressurechamber to cause said bearing to automatically pack itself to preventthe escape of the air or other elastic fluid about said bear- A stillfurtherobject is to provide in an apparatus of this character, thepressure chamber of which will have a spherical interior and a depressedportion adjacent to the outlet thereof, whereby the metal poured fromthe ladle will be collected and positioned below the lines of curvatureof the compression chamber and the pressure exerted by the compressedair will be directed upon the top of sameso as to avoid the splashing ofmetal due to the obstruction of the direction of flow of the air asdefined by the sides of the pressure chamber.

A still further object is to provide an apparatus wherein a measuredquantity of metal substantially equaling the volume of metal necessaryto form a given casting, will be introduced to the pressure chamber witheach actuation of the apparatus, thus avoiding the clogging or foulingof the apparatus,

and causing the entire quantity of metal used with each casting to beremoved from the apparatus and the mold, at the end of each castingoperation to insure clean metal free of oxid and dross for each casting.

A still further object is to provide an ap-. paratus of this characterembodying therein means whereby a suctionmay be applied so as to relievethe pressures within the mold at those points where.the inflowing metalwould ordinarily pocket and compress the air, thus directing the flow tothese particular localities within the mold and avoiding surfaceimperfections as w ell as accomplishing that venting of the moldessential to casting under pressure, which apparatus will alsoembodymeans for feeding themetal under pressure..-

A still further object is to provide an apparatus of this characterwherein all parts thereof are readily accessible after each castingoperation in order that the entire, measured quantity of metal may beremoved from the mold, the pressure chamber, in case of an imperfectcasting, and the ingate to the mold.

A still further object-is to provide an apparatus of this characterhaving an open ingate and no moving part in or about same thus avoidingall such parts which, when used with higher fusing metals, becomeinoperative through brazing, wearing, warping or assimilation by themetal being cast."

* A still further object is to provide an apparatus which shall consistof a bi-part mold, a bi-part pressure chamber and a bi 7 nance of thepressure within the pressure chamber, and a still further object is topro vide an apparatus of this character which will be simple in designand inexpensive to manufacture. a

The invention consists in a process, art or method of casting fluidmetal which consists broadly in pouring a measured quantity of fluidmetal from within an inclosed cham-' her into a metallic mold andforcing and compressing the =metal by followingit up with an elasticfluid under high pressure, and in-such other novel features of saidmethod or art; and in the novel features of construction and combinationof parts of the apparatusfor carrying out said prpcess, all ashereinafter set forth and described and'moreparticularly pointed out inthe claims hereto appended.

Referring to the drawings :Figure 1 is a sideelevation of an apparatusembodying my invention adapted to carry out or performmy'aforesaidmethod or art; Fig. 2 is a vertical section of theapparatus shown in Fig. 1; Fig. 3 is a View of said apparatus similar tothat shown in Fig 1, excepting ditional that the sectional mold andpressure chamber are shown partly opened; Fig. 4 is a plan View of theapparatus shown in Fig. 3; Fig. 5, is a detailed view of one member of asectional mold; Fig. 6 is a detailed View ofgthe ladle showing the bowlthereof in section, and Fig. 7 is a plan view of the said ladle.

Like letters refer to like parts throughout the several views.

In the practice of my aforesaid method or art, I aim to secure all ofthose advantages of pouring molten metal secured by the brdinary foundrypracticefwith the adadvantages found in the more re. cently developedpractice of casting molten metal under pressure in metallic molds. To

secure the desired results, the handling-of the molteni'netal must besuch as to avoid the completion of the casting operation by. either ofthese practicesyanecessity which in thepractice of.my method or artpre-" sents a clear line of demarcation between the steps, principles orcharacteristics of these two practices utilized, which in someinstances, is however, so narrow as to result, to' all intents andpurposes, in a substantially continuous pr simultaneous application ofthe two principles.

In carrying out my (aforesaid method or art, the first essential is aninclosed'pressure which it will be concentrated during the casting oeration so as to form a moving barrier o molten metal between the moldand the pressure chamber, flowing toward the former, the movement ofwhich will be accelerated by the application of elastic fluid pressure.within the chamber, and the presence of which in the said constrictedchannel will exclude the elastic fluid under compression from said moldso that the entire expansive force of said fluid will be utilized 1naccomplishing the rapid charging of the mold and the compression of themolten metal simultaneously with its entrance to said mold and the lastessential is the use of a measured quantity of molten metal, and bymeasured quantity I mean a quantity ap- .proximating inweight and bulkthe volume of the metal in the completed casting. This assumesimportance because of the necessity for eliminating the melting pots ofthe prior art, for preserving the quality of the metal and preventingits deterioration by reason of its impregnation with oxygen or othergases due to the action of the fluid under compression thereon, and forsecuring the desired degree of compactness of the metal throu'ghthe said.elastic fluid under sion, while it is within the mold.

With these four essentials in mind, I will-if now describe in detail,the manner of carry- 1 ing out my aforesaid method or art, which will bemore readil understood by referring to Figs. 2 and 5 o ings.

The metal to be used in casting is melted or reduced to alfluid state ina separate;

melting pot or crucible, the usual precautions being taken to preservethe purity of the metal and maintaining it at the desired .temperature.This molten metal as it is to be used, is removed from thismelting ot(not shown in the drawings) by a la le, which referablyv is insulated toprevent heat radiation, and the filled ladle is laced within thepressure chamber. By re erence to said Figs. 2 and 5 it will beobservedthat the mol with throu h an ingate constricted relative to the sai(pressure chamber is disposed above the and the walls of thepressure-chamber areclosed after the ladle .is placed in} the latter,the pressures within the moldand the said chamber at this stagefbeingbalanced so as to have an equilibrium of .pressures on both 30 sides ofthe said ingate. Under normal the accompanying draw-- proper and i'sjiincommunication therevpressure chamber. The mold I 1gb. comprisconditionsthis pressure will be one atmosphere, although if desired, as will morefully appear hereinafter, a more or less perfect vacuum may beformedwithin the mold and the pressure chamber, in order to facilitate thecharging of the mold, or to prevent the imprisonment of air between theinflowing metal and the sides of, or obstructions, or abutments in, themold, by directing the flow of metal, in intricate .castings, as itenters the mold. The same result under most conditions can be secured byfreely ventingthe mold adjacent to said abutments or obstruct-ions; andthe use of a vacuum or partial vacuum, While in most cases desirable, isnot absolutely necessary in the practice of my said fnethod or art. Itwill be observed, however, that whether or nota vacuum is used thepressures throughout the apparatus when it is ready for carrying on mymethod or art is the same. The apparatus being thus prepared, the ladlecontaining the molten metal is overturned, pouring the contained moltenmetal directly into an ingate of a mold or in a sub-chamber in thepressure chamber, and thence to the ingate of the mold. When so poured,the molten metal will be concentrated within said ingate or saidsub-chamber and said ingate, either of which is constricted relative tothe pressure chamber, and will begin to flow by gravity through saidingate into the mold. Immediately after, simultaneously with, thepouring of the molten'metal, air or other gas under high pressure, thepressure varying according to the nature of the casting being made, isadmitted to the pressure chamber in a manner to prevent an air jet fromimpinging directly upon the molten metal and to result in the subsequentexpansion of this air accomplishing the charging of "the metal. Vere anair jet to impinge directly upon the surface of the molten metal, itwould have a tendency to' splash same about the pressure chamber,imprison air in the metal being charged, and possibly pass through themetal in the ingate and enter the mold before the metal itself.

It will be observed that as the metal is poured into the constrictedpassage forming the ingate to the mold, it is flowing under conditionsfound common in foundry practice and forms a moving barrier of moltenmetal between the pressure chamber and the mold, there being an euilibrium of pressures on the opposite si es of said moving barrier. Aspressure is applied to the pressure chamber; however, this equilibriumis destroyed with the preponderating pressure on the side toward thepressure chamber. This destruction of the equilibrium of pressures,serves to suddenly accelerate the flow of the metal converting theentire charge into a metallic ram as it enters the mold or practicallyand forcing it to all parts thereof, filling up all cavities andinterstices within the mold practically instantaneously. The saidpressure, back of the inflowing metal, by its continued expansion servesto compress the metal substantially simultaneously with its entry intothe mold, such compression being by either a direct superficial,pressure upon the last of the metal entering the mold, or through thevolume of metal flowing thereto.

In carrying out said method or art I have found that irrespective of thefusing point of the metal used, it will set practically simultaneouslywith its entrance to the mold, so that it is essential to my method orart that the pressure for compacting or compressing the metal in themold be applied substantially simultaneously with the entrance of themetal to the mold in order to insure perfect castings, thespecific'gravity of the metal used regulating the instant of applicationof the pressure. The use of a vacuum in carrying out my process has, asits main advantage, the elimination of air within the mold. This is notfor the purpose of reducing the pressure necessary'to secure the desireddegree of compression of the metal, but it is apparent that air in themold might be compressed and imprisoned between the metal and a portionof the mold, or in the metal itself in case its entrance to the moldshould be by a swirling motion and thus cause an imperfect finish orblow holes in the casting, which condition would be largely obviated bya reduction of the volume of air in the mold prior to the entrance ofthe metal.

In certain intricate castings, the form of the mold must be such as topresent small angles or pockets therein, to retard, or impart a naturaltendency to, the flow of the metal which through the rapid setting orchilling of the metal being cast, might have a tendency to eitherimprison air at this point, or retard the flow of metal in the mold toan extent to permit it to chill or set before the mold is completelyfilled. To obviate this possibility, I arrange at any such point anadditional vent or conduit leading to a vacuum chamber or pump, notshown, so as to not only reduce the resistance at such a point butinduce a natural flow of the metal to any point which, under normalconditions, would be less readily filled with the molten metal. Thisdirection or control of the inflowing metal is essential only in certaintypes of castings and therefore is not absolutely essential to theinvention considered broadly. It has, nevertheless, an important bearingupon the continued practice of the invention and as a minor detail is adesirable feature in the successful practice 'of my method or art.

In the accompanying drawings I have illustratedan apparatus embodyingthe essential characteristics necessary in carrying out my heretoforedescribed method or art. This apparatus comprisesa base or frame (I.having straps or thereon in which is mounted a mold plate I). To adaptthis plate to molds into which the metal must flow, at different angles,I preferably mount said, plate I) pivotally in said straps. Carried onopposite sides of said plate I) are a plurality of guide rods Z), theouter ends of which are secured to a rod 0 carried onan adjustablestandard a. It will be observed that] the pitch of the late I) may thusbe regulated a I. by raising or owerlng the .rod 0 Slidably mounted onthe rods 6', by means of elongated bosses thereon, is a second moldplate 6 parallel with, and oppositely disposed relative to, the.-.plateb. The rods 1') are arranged at a point intermediate the top and bottomof said plates 11 b in order to.

avoid over-balancing of these plates. The

plates 7) b .are adapted to have secured thereto, in any desired manner,the parts (Z (Z of a sectional metallic mold adapted to shape. the fluidmetal. The plate I), as will more fullyappear hereinafter, being movablerelative. to the late 6 upon the guides b, it will be on erstood thatthe parts of the mold may be readily separated for the purpose ofejecting a finished casting.

Secured to the bl-part mold d d are the parts e e of a sectional headforming the pressure chamber 1, the parts 0 e of said head being adaptedto be separated, with the parts of the mold, for thepurpose ofintroducing the charge of molten metal thereto. It will be observed thatthe head containin the pressure chamber surmounts the mold so that theoperation of charging may be initiated through gravity. While I- haveshown a bi-parthead, such is merely a matter of convenience,and a heademploying any -means for permitting access to the pressure chamber willbe the full equivalent of the head described. Leading to the pressurechamber 1 is an air line 9 controlled by a valve g which may or may notcontain a vent as desired. Opening into'the pressure chamber f is abearing h in the head, which bearing is adapted to be opened when thehead is opened ii order to permit the mounting of the pouring ladletherein. This hearing is below the inlet of the. air line 1 and at oneside thereof, to position the ladle di"- rectly below said air inlet.The bearing h is tapered with the larger end adjacent'tm 'and saidshank-is immaterial as the same will occur only after the ladle has beenturned to pour the metal.

said mold plate I) is reciprocated on the rods 71 by a lever Zpivot-ally mountedon the rod n, and having its short arm ivotallyconnected to the said yoke. Suitable reinforcing or locking means forthe head 1'- o are provided, such means in the simplest formcmisistingof a vise Z pivotally mounted on one of the parts of said head as c andcarrying an ad ustment screw Z adapted to engage the other part of thehead (2. for the purpose of holdingthe abutting surfaces of said parts ac in engagement with each other, irrespective of the pressures withinthe pressure chamber f. The dimensions and adjustment of the yoke j andlover Z! are such that when the mold is closed,'these' parts will bealined, thus trai'ismitting all strains to the rods 1) through the saidmechanism and the rod 0'.

.Eith'er of the parts (Z (Z' of the mold may be fitted with a suitableejector mechanism indicated in the drawings by the letter in. Asectional mold adapted to be opened after the completion of a castingand provided with an ejector mechanism for removing the casting, is oldand well known in this art and no claim of invention as to this featureper se is made, such being merely a neces sary incident in any castingapparatus utilizing metallic molds. The details of these .features aretherefore immaterial to the in vention and any desired construction ofsectional mold and ejector mechanism may be utilized.

In my improved apparatus it will be observed, the pressure chamber andthe mold constitute practically the entire a paratus utilized ineffecting the charging o the latter, which construction not only aflordscompactness and simplicity, but permits the. adaptation of the apparatusto each particular casting.

his to be observed that the air line 9 is connected to the stationarypart ofthe mold head 0 the feed pipe being flexible at some spherical inshape for the threefold purpose v of limiting the dimensions thereof,providing the proper clearance for the ladle 1n turning, and fordirecting the flow of air adjacent to the bottom thereof so as to avoida=tendency of the air to act indirectly in a jet upon the molten metal.The chamber f is in direct communication with the interior of the moldthrough a constricted passage way. the dimensions of which will varywith the size and character of the casting to be made, with the metalbeing cast and to insure the proper application of the air or otherfluid under compression to the molten metal. The width of this passageway will under all conditions, however, necessarily he constrictedrelative to the pressure chamber. In the preferred form of the inventionas shown in the accompanying drawings, the passage way consists of aningate n leading directly to the interior of the mold, and a sub-chambero-of much greater capacity than the said ingate having a wide mouth,opening into and below the curve of the bottom of the pressure chamber.A graduated passage way between the pressure chamber and the interior ofthe mold is for the purpose, not' only of controlling the How of metalinto the mold and limiting the dimensions of the sprue, but for thefurther purpose of momentarily checking or retarding the flow of themetal after it is poured, so as to insure the application of thepressure at the proper instant. The enlarged head of the passage waywhich I have termed the sub-chamber 0, permits the metal contactingrvith the sides thereof to set Without interfering with the applicationof pressure to a sufficient volume of metal to fill the mold. Inmeasuring the quantity of" molten metal to be used with each casting,allowance must be made for the shell of metal which will be formed inthis sub-chamber and in the ingate itself. The sub-chamber 0 is largeenough to receive the contents of the ladle and retain it below thepressure chamber in a osition where the air currents when admitte to thepressure chamber will pass over same in a manner which will be morefully described hereinafter.

It will be observed that the ingate is unobstructed in any way and that,no sprue cutter or other moving part is necessary to insure theproduction of a perfect casting. This feature is of great importance aswhen using metals having a high fusing point, a sprite cutter, arrangedas it would be, at the point where the temperature would be the highest,could not withstand the ordinary wear and tear of use. and wouldresultin the frequent break down of the machinewith the resultantnecessity for renewal of parts. The high temperatures would also make itdifficult to secure a-proper fit, and the warping of the metal in thecutter would make it practically inoperative. In the ordinary up-feedpressure casting machine, a sprue cutter is necessary to close the moldand prevent the portion of the metal forced thereinto under pressureflowing by gravity back to the pressure pot or cylinder. In a machine ofthe character heretofore described, wherein gravity is utilized incharging, it is not required to provide any means for the purpose abovereferred to.

Referring more particularly to Fig. 5 of the drawings,1 sometimespartially surround the interior of the mold with a channel as p whichchannel is in communication through a duct p with a suction box, orpump, not shown. Leading from this channel are a lurality of shallowducts p leading to the Interior of the mold through which the air in themold and the pressure chamber may be drawn for the purpose of reducingthe pressures in these parts. The expedient of creating a partial vacuumwithin a mold is old in the art of casting, and I make no claim ofinvention thereto broadly. In arranging the ducts 32 however, I not onlyvacuate the mold but so dispose the duets with regard to the naturalflow of the incoming metal as to direct the flow thereof to specialpoints in the mold where the natural tendency of the metal would beeither to pass same, or compress the air within the mold between it andthe sides of the mold.

I/believe it to be new to direct the flow of metal in the mold by meansof a suction or mechanism for creating such, at certain points, andintend to claim such.

Where a mold has a number of moving parts therein, the channel and ductarrangement heretofore described, mustbe varied to meet the conditionspeculiar to said type of mold; but would retain the essential featuresof the ducts p communicating with a suction box or pump through anintermedi ate chamber.

In carrying out my method or art or in using my heretofore describedapparatus, it is necessary to prevent heat radiation from the metalwhile it is being conveyed from the melting pot or crucible to thepressure chamber.

A ladle of graphite, fire clay or other similar refractory materialwould be desirable but as the ladle acts as a deflector and distributerfor the air jet such materials would not possess the requisite strength.To obviate this difliculty, I use a metallic ladle, the bowl of which islined or coated with graphite or fire clay, or both, said insulatedlining 1- being molded within said bowl and retained in place bysuitable anchors entering holes sunk part way through the metal of themold. It will be observed that I thus provide a rotary ladle the bowl ofwhich consists of reinforced refractory material, whereby heat radiationfrom the molten metal is prevented before pouring, and thereinforcement, after pouring, acts to receive and deflect the fluid jetwithout injury to the refractory lining. The curve of the ladle 9 whileon a shorter radius, conforms to that of the pressure chamber 1 so thatthe fluid jet as it enters the pressure chamber is deflected against thesides thereof for a sufficient distance to impart thereto a rotarymovement so that incase the air should follow the sides of the pressurechamber to the bottom thereof, it will have a direction of fiow whichwould carry it across the subchamber where, meeting an air current fromother sides, it would pass up into the bowl rather than in a jet uponthe metal in the sub-chamber. It will be readily observed that were themetal to project into the pressure chamber in the course of saidcurrents, the air currents would pick up such metal and splash it aboutthe chamber. The ladle 7 has an elongated handle q having thereon acircular shoulder adapted to engage the outside of the pressure chamberadjacent to the bearing h. The handle between said shoulder and the bowlof the ladle is tapered to conform to said bearing.

While the heretofore described apparatus is suitable for carrying out mymethod or art, it is apparent that said method or art may be carried onin any desired form of apparatus. v r

In the practice of my said art or method, a measured quantity of metalhaving been introduced to the pressure chamber in the I ladle, and thesaid chamber and mold closed,

and locked so as to withstand the pressures within same, the ladle isoverturned and the metal poured in-the same manner as is now common infoundry practice, the metal being delivered from'the ladle to theconstricted passage way between the pressure chamber and the mold,wherein the metal is accumulated and concentrated, substantiallysimultaneously. The, reduced discharge of said passage way will retardor momentarily check the flow of the metal, by gravity, into the moldand at this instantvfluid pressure is applied to said chamber, theexpansion thereof acting upon the molten metal in the passage way.- Itwill thus-be observed that ,the pressure is applied so as to follow upthe metal flowing by gravity into the mold, and that the metalitselfforms the only barrier between the pressure chamber and the mold. Thisinsures the charging of the mold under conditions which exclude thecompressed fluid from the metal being cast, which compacts the metalslightly, prior to its entrance to the interior of themold, and whichcompresses it substantially simultaneously with its entrance to saidmold.

By freely venting the mold at certain points or creating a vacuum orpartial vacuum throughout the apparatus, by means of ducts leading fromcertain points of the mold, the direction of the flow of the metalwithin the mold may be controlled so as to prevent blow holes in thecasting or imperfections in thefinish due to the setting or chilling ofthe metal before it entirely fills the mold, by reason of the pocketingof air in the metal or the compression of air be tween theincoming metaland the sides .of the mold.

It will be observed that as heretofore stated, the pressures within themold and the compression chamber are balanced prior to the applicationof'pressure, and that the pressure, when applied, destroys thisequilibrium of pressures with the preponderating pressure within thepressure chamber; and that furthermore, the sole function of the fluidplate b on the guide rods 1), away from the fixed mold plate 6. Beforeactuating the lever is it is necessary to disengage the vise I from thesection 6 of the head. Vhen so opened, the die may be smoked orotherwise coated to protect it from the molten metal, an expedient wellknown in this art. The ladle q is then filled with a predeterminedquantity of molten metal, and placed in the pressure chamber f,'-withthe tapered *portion of the handle in the tapered bearing It and theshoulder g abutting against the outside of the head .6 e. The lever k isthen lowered to close the plates 12 b and the mold and head sectionscarried thereby, the said lever and the yoke 7' being on a. horizontalcenter. when these parts are closed. If desired any suitable facepacking may be provided between the sections of the mold and the head.to minimize loss of. pressure through leakage. The vise Z is then swungso as to inclose both sections 6 e of the pressure chamber head, and theadjustment screw 1' set so as to clamp the sec-.

tions of said head together. When a vacuum is used, the mold is thenplaced in communication with a-suction box, or pump in any desiredmanner, through the duct 2, the channel p and the shallow duct 79'. Thiscreates a vacuum or partial vacuum within the mold, the pressure chamberand the passage way connecting same. These steps which in practicerequire only a fraction of a minute, preparethe apparatus for thecasting process; The ladle q' is then quickly overturned by means of itshandle 9' to discharge the molten met-a1 into the sub-chamber 0 andingate n, the refractory or insulating lining of said ladle preservingthe condition of the-metal while the apparatus is being prepared. Whenthe metal is thus poured, 1t begins to flow-by gravlty into the mold,the graduation of the subchamber and ingate, serving to retard this flowor check it momentarily so as to concentrate and accumulate practicallythe entire bulk of metal between the pressure chamber and the mold.Thereupon the valve y in the air line 9 is opened and quickly closedagain and air or other elastic fluid under heavy pressure is admitted tothe pressure chamber in a jet. The ladle q being completely overturned,is directly in the path of this jet, and serves to deflect it in alldirections giving it a direction coinciding with the interior of thepressure chamber. In case the currents thus created follow the walls ofthe chamber to the bottom thereof, they will meet above the sub-chamberand expand without affecting the surface of the metalthercin. The timeof application of the pressure will vary relative to the pouring of themetal, with the specific gravity of the metal, its condition, or thealloy being used, and it may be either practically simultaneously withthe pouring, or slightly thereafter. This pressure will be applied whilethe metal is still in the ingate and flowing toward the mold by gravityand it is apparent that the metal itself acts as the only barrierbetween the pressure chamber and the mold, and offers the onlyresistance to the pressure. This condition insures an ac celeration ofthe movement of the metal, and no air can penetrate the mass. This modeof operation has the further advantage that no limitation within reasonis placed upon the quantity of metal cast at a single operation, suchbeing dependent solely upon the size and strength of the apparatus, thecharacter of the die, and the capability of developing sufficientpressure. As the metal enters the mold, so far as I have been able todetermine, it is in a more or less compact stream and is substantiallyinstantly forced to all parts of the mold and compressed and compactedtherein by the pressure from the pressure chamber.

I have found that the conductivity of the metal in the mold, sub-chamberand ingate results in the chilling or setting of metal thereinpractically instantaneously, permitting a quick ejection of a casting,butleaving a quantity of metal within the sub-chamher and. the ingate.The action of the pressure, however, is so rapid as-to fill the moldfrom the molten metal not contacting with the metal of the apparatus,leaving a small sprue on the casting which may readily be removed afterthe casting is ejected. Itis apparent, therefore, that the mold shouldbe separable along a line passing through the sub-chamber 0 and in ate ato permit this sprue to be remove simultaneously with the completedcasting.

. The casting having been completed as described, the operation ofopening the die is repeated, and the ejector mechanism m operated tothrow the casting from the mold.

\Vhen the jet acts upon the reinforcement of the. ladle, it imparts anoutward thrust thereto which packs lhetapered portion of the handle 1 inthe tapered bearing h, thus packing the bearing against the highpressure prevailing in the pressure chamber.

By my method or art, and in my apparatus herein described I havesuccessfully cast, alloys rich in copper, and in aluminum, in additionto the so-called white brass, and the ordinary zinc mixtures known asWhite metals and have found that in all metal the castings contain noblow holes or-other defects due to the manner of casting same. In fact,the castings show a particularly fine grain, and are more solid anduniform than ordinary sand castings.

The apparatus must be adapted to each mold, and l have found that byvarying the direction of the flow of the metal through the ingate I cancast with better results from the same mold. Hence the standard 0 may belengthened or shortened to pitch the mold slightly in differentdirections in the manner heretofore described.

It is not my intention to limit the invention to the precise details asto the method or art, or the construction of the apparatus, as such maybe varied without departing from the spirit or scope of the invention. I

believe, however, that to cast brass or other high fusing metalssuccessfully, it is essential to utilize both gravity pouring and highpressure substantially as described and that a measured quantity ofmetal is an essential to this result; and I intend to claim suchbroadly.

Having described the invention, what I claim as new and desire to haveprotected by Letters Patent, is

1. The herein described process, method or art of casting fluid metalconsisting of pouring a measured quantity of molten metal from within aninclosed chamber into a metallic mold and thereafter forcing andcompressing the metal by following it up with an elastic fluid underhigh pressure.

2. The herein described process, method or art of casting fluid metalconsisting of pouring a nmasured quantity of molten metal from within aninclosed chamber into a metallic mold' and forcing and compress- .ingthe metal by subjecting it while it is pouring a measured quantity offluid metal from within an inclosed chamber into a constricted passageway leading to a metallic mold, and forcing and compressing the metalfluid under high pressure.

4. The herelndescribed process, method or art of casting fluid metalconsisting of pouring a measured quantity of fluid metal from within aninclosed chamber into a metallic mold, maintaining an equilibrium ofpressures within said chamber and. said mold while pouring, anddestroying the equilibrium of pressures with a preponderating pressurewithin .said inclosed chamber, whereby while the metal is flowing to themold by gravity its movement is accelerated andit is forced into andcompressed in' the mold under heavy pressure. 1

5. The herein described process, method or art of casting fluid metalconsisting of pouring-a measured quantity of fluid metal rom within aninclosed chamber into a constricted passage Way leadin to a metallicmold, maintaining an equililmium of pressures within said chamber andsaid mold while pouring, and destroying the equilibrium of pressureswith a preponderating pressure within said inclosed chamber, wherebywhile the metal is flowing to the mold by gravity its movement isaccelerated and it is forced into and compressed in the mold under heavypressure.

' 6. The herein described process, method or art of cast-ingfluid metalconsisting of pouring a measured quantity of molten metal rom within aninclosed chamber'into a me tallic mold and forcing and compressing themetal by subjecting 1t while it is flowing from said chamber to the moldto the expansion of an elastic fluid under high pressure.

7. The herein described process, method or art of casting fluid metalconsisting of ouring a measured quantity of fluid metal 10m within aninclosed chamber into a con.- stricted passage way leading to a metallicmold, and forcing and compressing the metalby subjecting it while it isflowing through said constricted passage way to the expansion of anelastic fluid under high pressure. P

8. The herein described process, method or art of casting fluid metalconsisting of pouring a measured quantity. of fluid metal from within aninclosed chamber into a metallic mold, maintaining an equilibrium ofpressures within said chamber and said mold while pouring, anddestroying the equilibrium of'pressures with a preponderq ating ressurewithin said inclosed chamber, where y while the metal is flowing. to themold by gravity its movement is accelerated and it is forced into andcompressed in the mold under heavy pressure. by the expansion of anelastic fluid under high pressure.

9. The herein described process, method or art of casting fluid metalconsist-ing of metal is flowing to the mold by gravity its movement isaccelerated and it is forced into and compressed in the moldunder heavypressure.

'10. The herein described process, method or art of casting fluid metalconsisting of pouring a measured quantity of-fluid metal from within aninclosed chamber into a metallic mold, reducing and maintaining theequilibrium of pressures within said mold and said chamber, and forcinand compressing the metalwhile it is owin said chamber to said mold byexpanding an elastic fluid under high pressure in said inclosed chamber.I

11. The herein described process, method or art of casting fluid metalconsisting of pouring a measured quantity of fluid metal from within aninclosed chamber into a constricted passage way leading to a metallicmold, reducing and maintainin the equilibrium of pressures within saimold, said passage way and said chamber, and forcing and compressing themetal while it is flowing through said passage Way to said mold by theexpansion oi an elastic fluid g 1 from by expanding an elastic fluidunder high pressure insaid inclosed chamber.

12. In an apparatus for casting fluid metals, the COIIlblIlfitlOIl Of asectional mold, a head forming a pressure chamber surmounting said moldand adapted to be opened whereby gravity will initiate the flow of fluidmetal to said mold, means forming a constricted passage way between saidpressure chamber and the interior of said mold, a receptacle adapted. tocontain a measured quantity of. molten metal and to be pivotally mountedwithin said pressure chamber and means whereby an elastic fluid undercompression may be introduced to said chamber to follow up the metalthrough said passage way and force it into, and compress it in, themold.

-13. In an apparatus for casting fluid metal, the combination of asectional mold, a head adapted to be opened forming a pressure chambersurmounting said mold whereby .gravity will initiate the flow of fluidmetal to said mold, means forming a graduatedfconstricted passage waybetween said pressure chamber and the'interior of said mold. wherebymetal will be accumulated and concentrated between said pressure chamberand said mold and form a moving barrier between said parts, a receptacleadapted to contain a measured quantity of molten metal and to bepivotally mounted within said pressure chamber and means whereby anelastic fluid under compression may be introduced to said chamber tofollow up the metal through said passa e way and force it into andcompress it in, t e mold.

14. In an apparatus for casting fluld metal, the combination of asectional mold, a head fogming a pressure chamber surmounting said moldand adapted to be opened, means forming a constricted passage waybetween said pressure chamber and the interior of said mold whereby anequilibrium of pressures maybe maintained in said mold, said pressurechamber, and said passage way whereby gravity will inltiate the flow ofthe fluid metal to said mold through said passage way, a receptacleadapted to contain a measured quantity of molten metal and to bepivotally mounted within said pressure chamber, and means whereby anelastic fluid under compression may be introduced to said chamberdestroy the equilibrium of pressures within the apparatus with apreponderating pressure within said pressure chamber and follow up themetal, through said passage way and force it into and compress it in,the mold.

15. In an apparatus for casting fluid metal, the combination of asectional mold, a head adapted to be opened forming a pressure chambersurmounting'said mold whereby gravity will initiate the flow of fluidmetal to said mold, means forming a subchamber opening into and belowsaid pressure chamber and an ingate connecting said sub-chamber with theinterior of said mold, said sub-chamber being constricted relative to,said pressure chamber and said in te being constricted relative to saidsub-c amber, a receptacle adapted to contain a measured quantity ofmolten metal and to be pivotally mounted within said pressure chamberand means whereby an elastic fluid under compression may be introducedto said chamber to follow up the metal through said subchamber and saidingate and force it into and compress it in, the mold.

16. In an apparatus for "casting fluid metals the combination of asectional mold,

a head forming a spherically shaped pres sure chamber surmounting saidmold and adapted to be opened whereby gravity will initiate the flow offluid metal to said mold, means formin a sub-chamber opening into andbelow sai pressure chamber and an'ingate connectin said sub-chamber witthe interior of said mold, said sub-chamber being constricted relativeto said pressure chamber and said ingate being constricted relativeto-said sub-chamber, a receptacle adapted to contain a measured quantityof molten metal and to be pivotally mounted within said pressure chamberand means and said in whereby an elastic fluid under compression may beintroduced to said chamber to. follow up the metal through saidsub-chamber to and force it into and compress it in, t e mold.

17. In an apparatus for casting fluid metals the combination of asectional mold, a head forming a spherically shaped pressure chambersurmounting said mold and adapted to be opened whereby gravity willinitiate the flow of fluid metal to said mold, means formin asub-chamber opening into and below sai pressure chamber and an insaidsub-chamber with the.

gate connectin interiorof sai mold, said sub-chamber be ing constrictedrelative to said pressure chamber and said ingate being constrictedrelative to said sub-chamber, a ladle having a bowl conforming to, butof smaller dimensions than, said chamber, means whereby said ladle ispivotally mounted within said pressure chamber and an air line enteringsaid chamber above the pivotal point of said ladle, whereby said ladleafter the metal' is poured therefrom, becomes an air shield fordeflecting the jet and preventing its entering the metal in, saidsub-chamber, and an elastic fluid under compression may be introduced tosaid chamber to follow up the metal through said passage way and forceit into and compress it in, the mold.

18. In an apparatus for casting fluid metals the combination of asectional mold, a head forming a spherically shaped pressure chambersurmounting said mold and adapted to be opened whereby gravity willinitlate the flow of fluid metal to said mold,

means forming'a sub-chamber opening illtOx and below sai pressurechamber and an inate connectin said sub-chamber with the interior of saimold, said sub-chamber being constricted relative to said pressurechamber and said ingate being constricted relative to saidsub-chamber, aladle having a refractory lining and a metallic reinforcement covering,the outside thereof, and a bowl conforming to, but of smaller dimensiongthan, said chamber, means whereby said ladle is pivotally mounted withinsaid pressure chamber and an air line entering said chamber above thepivotal point of said ladle, whereby said ladle after the metal ispoured therefrom, becomes an air shield for deflecting the jet andpreventing its entering the metal in said sub-chamber, and an elasticfluid under compression may be introduced to said chamber to follow upthe metalthrough said passa e way and force it into and compress it in,t e mold.

19. In an apparatus for castin fluid metals, the combination of asectiomfi mold, a head forming a ressure chamber surmounting said moland adapted to be opened, means forming a constricted passage waybetween said pressure chamber and librium of pressures may be maintainedin.

said mold, said pressure chamber and said passage way whereby gravitywill initiate the flow of the fluidmetal to said mold through saidpassage way, means for reducing t e pressures within the apparatus, areceptacle adapted to contain a measured quantityof molten metal and tobe pivotally mounted within said pressure chamber, and means whereby anelastic fluid under compression may be introduced to'said chamber 'todestroy the equilibrium of pressures within the ap aratus with apreponderating pressure within said pressure chamber and follow up themetal, through said passage Way and force it into and compress it in,the

mold. v

20. In .an apparatus for castin fluid metals, the combination of asectiona mold, a head forming a pressure chamber surmounting said moldand adapted to be opened, means forming a constricted pas sage waybetween said pressure chamber and the interior of said mold whereby anequilibrium of ressures may be maintained in said mold, sald pressure'chamber and said passage way whereby gravity will initiate the flow ofthe fluid metal to said mold through said passage way, means for reducmgthe pressures within the apparatus, comprising a shallow duct formed inthe mold lock'leading to a definite point or points in the interior ofthe mold whereby the pressure is reduced at such points, a main channelcommunicating with said duct or ducts,

and means for creating a vacuum within said last mentioned channel, arece tacle adapted to contain a measured quantlty of molten metal and tobe pivotally mounted within said pressure chamber, and means whereby anelastic fluid under compression may. be introduced to said chamber todestroy the equilibrium of pressures within the apparatus with apreponderating pressure within said pressure chamber and follow u' themetal, through said passage way and orce it into and compress it in, themold. v 1

21. .In an apparatus for casting fluid metals, the combination of asectional mold, means for closing and locking the said mold, a sectionalhead carried by and. movable with the sectionsof said mold respectively,

and forming a pressure chamber surmount ing said mold whereby gravitywill initiate the flow of fluid metal to said mold, supplemental lockingmeans for the sections of whereby an elastic fluid under compres-fi sionmay be introduced to said chamber to follow up the metal through saidpassage way and-force it into and compress it in, the mold. j a

22. In an apparatus for casting fluid metals, the combination of asectional mold, a head forming a ressure chamber surmounting said moland adapted to be opened whereby gravity will initiate the flow of fluidmetal to said mold, means forming a constricted passage way between saidpressure chamber and the interior of said mold, a receptacle adapted tocontain a measured quantity of molten metal and to be pivotally mountedwithin said pressure chamber, means whereby an elastic fluid undercompression may be introduced to said chamber to follow up the metalthrough said passage way and force it into and compress it in, the mold,and means for tilting said mold and said head to control the directionof the flow of metal through said pas-' sage way to said mold.

23. In an apparatus for casting fluid metals the combination of asectional mold,

a head forming a pressure chamber surmounting said mold and vadapted tobe opened, whereby specific gravity will initiate the flow of the'fluidmetal to said mold, the said head and the walls of the opening thereofhaving a tapered bearing, means forming a constricted passage waybetween said pressure chamber and the interior of said mold, a ladle thehandle of which is tapered to conform to said bearing and which has ashoulder thereon adapted toengage the exterior of said head, said ladlebeing adapted to'contain a measured quantity of molten metal and meanswhereby an elastic fluid under compression may be introduced to saidchamber to follow up the metal through said passage way and force itinto and compress it in, the mold.

9 'In witness whereof, I have hereunto affixed my signature this 11thday of January, 1909, in the presenceof two witnesses.

HERMAN H, DOEHLER.

Witnesses T. T. WENTWORTH, GEORGE MGCAY.

